• Wind and Structures
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• v.23 no.3
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• pp.171-189
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• 2016

An adjustable, louver-type wind barrier was introduced in this study for improving the running safety and ride comfort of train on the bridge under the undesirable wind environment. The aerodynamic characteristics of both train and bridge due to this novel wind barrier was systematically investigated based on the wind tunnel tests. It is suggested that rotation angles of the adjustable blade of the louver-type wind barrier should be controlled within $90^{\circ}$ to achieve an effective solution in terms of the overall aerodynamic performance of the train. Compared to the traditional grid-type wind barrier, the louver-type wind barrier generally presents better aerodynamic performance. Specifically, the larger decrease of the lift force and overturn moment of the train and the smaller increase of the drag force and torsional moment of the bridge resulting from the louver-type wind barrier were highlighted. Finally, the computational fluid dynamics (CFD) technique was applied to explore the underlying mechanism of aerodynamic control using the proposed wind barrier.

• East Asian Economic Review
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• v.24 no.4
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• pp.441-468
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• 2020

Capital inflows have a strong presence that influences destination countries' development of institutions, which can in turn help resuscitate a stopped economy and re-attract capital that was lost during crises such as the recent public health crisis. While the previous literature emphasizes the mechanism that foreign investors press or even threaten the local government for change, this paper explores empirically whether institutional improvement can be achieved through the channel that host countries voluntarily reform institutions in anticipation of potential investments predicted by the exogenous geographical and cultural characteristics of the recipient countries. Given that countries with better institutional quality can accumulate larger FDI stocks, we still find that the need for more FDI, in contrast to FPI and debt, gives higher incentives to host countries to strategically improve their institutions before seeking capital overseas. Moreover, the predicted FDI exerts more prominent impacts on institutions on constraining elite than those involved in launching a business, enforcing contracts, and protecting properties. The results imply that a long-run plan for upgrading elite constraint institutions is crucial for a post-pandemic FDI reboot.

• The Journal of Korean Society for School & Community Health Education
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• v.3
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• pp.1-13
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• 2002

Female university students generally have a lower intake of nutrition compared to other age groups due to their adverse interests in their appearance. Drinking, smoking, too much weight control, accumulation of psychological and physical stress are causes of inadequate diet. The result is deterioration of hair health. Establishment of good diet and hair care is the foundation of a healthy hair in adulthood. For this reason, there is a great need for a healthy hair care. The data from a questionnaire survey was analyzed with 800 female undergraduate students responding. Seventeen universities were included in the study, 8 of which were from Seoul, 6 from other large cities and 3 from smaller towns. The objective of this study is to investigate the correlations of these factors and to provide preliminary data for developing an effective hair care education program. Results include the following: 1. Knowledge score of hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 2. Attitude score towards hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 3. Behavior score towards hair care was higher for students with greater family income, allowance, interest in appearance. These factors had meaningful effect on the statistics of this study. 4. The correlation study between knowledge, attitude and behavior showed that higher the knowledge and attitude, better the behavior. 5. The analysis of factors effecting hair care behavior showed that interest in health, acknowledgement of current hair condition, total family income were a viable factor in predicting hair care behavior. The predictability of regression model is 38.9 %($R^2$) Therefore, in order to maximize the hair care behavior, consistent and systematic study should be earned out to develope an effective education program to improve health interest.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.76-92
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• 2002

OECD/PISA(Programme for International Student Assessment) is significant in that it is the first international comparative study assessing 15-year-old students' scientific literacy. Based on Korean students' results of percent correct in 35 science items, several characteristics such as followings were revealed. First, from the perspectives of science application area, Korean students showed the highest achievement in the area of 'science in technology' followed by in the areas of 'science in life and health' and 'science in earth and environment'. Male students achieved significantly better than female counterparts in all three areas. Second, the achievement in items of science knowledge was significantly higher than in items of scientific processes. Whereas the achievement difference between science knowledge- and scientific process items was larger for male students. Third, from the perspectives of application contexts, Korean students showed the highest achievement in the historical context and the lowest achievement in the personal context. Fourth, from the perspectives of item format, Korean students performed significantly better in open-constructed items rather than in multiple-choice items. Fifth, Korean students showed low performance in items of biotechnology and environment-related issue, which was more prominent for female students. Sixth, whereas male students performed significantly better than female students in most aspects, it is noteworthy that there was no significant gender differences in items of scientific processes and females performed significantly better than male students in open-constructed items which require long sentence.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.209-214
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• 2012

Indigo crop, Persicaria tinctoria H. Gross is an annual plant containing natural colorant, the blue dye indigo, and local cultivars had been cultivated to produce natural indigo for textile dyeing in Korea since ancient times. Naju No. 2 is a new mass-selected line from the mother population, Naju Local cultivar. In this study, two breeding lines of Naju Local and Naju No. 2, have been cultivated in four different locations, the South regions of Korea, to compare plant growth and yield characteristics between two lines. Naju No. 2 was higher in plant height, and Naju Local has more 1st branches. Naju No. 2 has larger leaf area and higher width/length ratio of leaf, showing the round leaf type as morphological stable character without regional differences. Though there was considerable regional variation in fresh and dry top weight of harvested plant, the significant difference of plant weight between two lines were not shown. The ratio of leaf to total shoot of dry weight of Naju No. 2 was higher than one of Naju Local, indicating that Naju No. 2 has better yielding of colorant which is synthesized mostly in leaf. Naju No. 2 contained more Niram (crude indigo extract) and indigo, and showed much blueness at dyeing of silk using fresh leaves than Naju Local. We concluded that a new line, Naju No. 2 could be a superior cultivar due to having higher leaf yield and better quality of natural colorant than Naju local cultivar.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.35-42
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• 2004

This research describes that the cutting characteristics and tool wear behavior in the micro cutting of three kinds of wear resistant cemented carbides (WC-Co; V40, V50 and V60) using PCD (Poly Crystalline Diamond) and PCBN (Poly crystalline Cubic Boron Nitride) cutting tools by use of the SEM (Scanning Electron Microscope) direct observation method. The purpose of this research is to present reasonable cutting conditions from the viewpoint of high efficient cutting refer to a precise finished surface and tool wear. Summary of the results is as follows: (1) The cutting forces tend to increase as the increase of the weight percentage of WC particles, and the thrust forces was larger than the principal forces in the cutting of WC-Co. These phenomena were different from the ordinary cutting such as cutting of steel or cast iron. (2) The cutting speed hardly influenced the thrust force, because of the frictional force between the cutting tool edge and small WC particles at low cutting speed region such as 2$\mu\textrm{m}$/s. It seemed that the thrust cutting force occurred by the contact between the flank face and work material near the cutting edge. (3) The wear mechanism for PCD tools is abrasion by hard WC particles of the work materials, which leads diamond grain to be detached from the bond. (4) From the SEM direct observation in cutting the WC-Co, it seems that WC particles are broken and come into contact with the tool edge directly. This causes tool wear, resulting in severe tool damage. (5) In the orthogonal micro cutting of WC-Co, the tool wear in the flank face was formed bigger than that in the rake face on orthogonal micro cutting. And the machining surface integrity on the side of the cutting tool with a negative rake angle was better than that with a positive one, as well as burr in the case of using the cutting tool with a negative rake angle was formed very little compared to the that with a positive one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.473-482
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• 1998

In this paper, characteristics of the wide band microstrip antennas with parasistic element are analyzed by the Finite Difference Time Domain(FDTD) method, and antenna parameters are optimized to get maximum bandwidth, retern loss, input impedance, and radiation pattern are calculated by Founier transforming the time domain results. The characteristics of the antenna are varied and the bandwidth of the antenna is broaded as a length and a width of the driven element, a gap of the driven element and the parasitic element, a width and a length of parasitic element. So the different patchs are resonating at different frequencies and this multipule resonance increase the bandwidth. The Results of the calculation and measurement, the size of the antenna with parasitic element is about a twice larger than a microstrip antenna, but bandwidth is four times better than a microstrip antenna. And these results were in relatively good accordance with the measured values.

• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.9-13
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• 2004

Perylene is an interesting material known to have P-type and N-type characteristics at the same time. We prepared perylene thin-films in ultrahigh vacuum with two different deposition rates of 0.1 $\AA$/s and 1.0 $\AA$/s in order to study the dependence of film characteristics on the growth condition. The smaller average grain size with larger surface coverage as well as the better crystallinity were observed on the perylene film prepared under 1.0 $\AA$/s deposition rate in x-ray diffraction (XRD) and atomic force microscopy (AFM) study. For studying electrical property of the film, perylene organic thin-film transistor (OTFT) with gold contacts was fabricated on $SiO_2$/Si surface in UHV condition. The prepared perylene OTFT device shows P-type characteristic. The obtained hole mobility in the current-voltage characteristic curve was$2.23\times10^{-5}\textrm{cm}^2$/Vs.

• International journal of thyroidology
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• v.10 no.2
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• pp.96-101
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• 2017

Background and Objectives: Anaplastic thyroid carcinoma (ATC) is commonly related with concurrent differentiated thyroid carcinoma (DTC). We aimed to examine the clinicopathologic characteristics, prognosis and gene expression of DTC with anaplastic foci. Materials and Methods: Eighteen patients with DTC with anaplastic foci were enrolled in this study. To compare the clinicopathologic characteristics and prognosis of anaplastic foci subjects with conventional ATC or DTC, we additionally included 12 ATC and 1030 DTC patients who diagnosed during same period. Immunohistochemistry was performed to check the gene expression in anaplastic foci and DTC component. Results: In anaplastic foci group, tumor size was larger ($2.5{\pm}1.3$ vs. $1.2{\pm}0.9cm$, p=0.001), distant metastasis was more frequent (11.1 vs. 0%, p=0.000) and 1-year survival rate was low (88.9 vs. 100%, p=0.000) than DTC group. In contrast, compared with ATC group, anaplastic foci group showed younger age at diagnosis ($50{\pm}16$ vs. $63{\pm}18years$, p=0.039), smaller tumor size ($2.5{\pm}1.3$ vs. $3.8{\pm}1.4cm$, p=0.027), less distant metastasis (11.1 vs. 41.7%, p=0.084) and longer 1-year survival rate (88.9 vs. 25.0%, p=0.001). Expression of p53 protein was observed in 100% of anaplastic foci, ATC and 12.5% of papillary thyroid carcinoma component. Conclusion: DTC with foci of anaplastic transformation has a worse prognosis than DTC, but a better prognosis than ATC. Our results support that DTC with anaplastic foci was intermediate state from DTC to ATC.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.2
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• pp.160-167
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• 2015

The purpose of this study was to investigate the correlation of Intima-Media Thickness of common carotid artery(CCA-IMT) and The Second Derivative of Photoplethysmogram Waveforms(SDPTG). 38 subjects with acute ischemic stroke were recruited from the patients admitted to Dong-Eui Medical Center from the June 2013 to January 2014. We assessed 38 patient's SDPTG data and CCA-IMT data by B Mode ultrasonography. then 38 subjects were divided into two groups by the CCA-IMT difference; CCA-IMT 〈 0.8 mm group(n=11), CCA-IMT $$\geq_-$$ 0.8 mm group(n=27). We analyzed their characteristics, risk factor, blood test result, life style by CCA-IMT difference. As a result, Age, Hypertension were significantly higher in the CCA-IMT $$\geq_-$$ 0.8 mm group then in the CCA-IMT < 0.8 mm group. Regular exercise were significantly higher in the CCA-IMT < 0.8 mm group then in the CCA-IMT $$\geq_-$$ 0.8 mm group. The result of Multiple regression analysis on the factors affecting the CCA-IMT was hypertension, total cholesterol, age. and The result of Pearson's Correlation analysis on CCA-IMT and SDPTG is that e/a ratio, SDPTG AI were respectively and significantly correlated with CCA-IMT. According to the analysis, the Relationship between CCA-IMT and SDPTG in Ischemic Stroke Patients were founded. We suggest that further investigation with larger and better controlled trials of the Relationship between CCA-IMT and SDPTG could contribute to better understand the effects of risk factors on atherosclerosis.